Minimizing of charge recombination by Nb2O5 addition in dye-sensitized solar cells

Abstract Investment in renewable energy sources has increased in recent decades because of the environmental impact caused by the non-renewable energy sources burning. Regarding to the available renewable energy technologies, the conversion of solar energy into electrical energy using photovoltaic devices, especially dye-sensitized solar cells (DSSC), stands out. In this study, we investigated the recombination reactions of DSSCs containing ZnO and Nb2O5 using electrochemical impedance spectroscopy, intensity modulated photovoltage spectroscopy, intensity modulated photocurrent spectroscopy, and charge extraction. The addition of Nb2O5 to the ZnO cells reduced recombination effects, and the 5% Nb2O5 cell presented the best photovoltaic parameters, having an electron lifetime of 0.18 s, collection time of 0.01 s, and efficiency of 2.39%.